Heretofore, when a polarizing layer in a polarizing element such as a polarizing lens is formed by aligning a dichroic coloring agent by deposition on an alignment film on the surface of a substrate, a film of silica (SiO2) formed by vapor deposition has been considered to be suitable as the alignment film. For example, a polarizing element which comprises a polarizing layer and a protective layer disposed on the surface of a transparent substrate and an inorganic intermediate layer disposed between the transparent substrate and the polarizing layer as the alignment film, is proposed (for example, refer to Patent Literature 1). The inorganic intermediate layer comprises silicon oxide, a metal oxide or a mixture of silicon oxide and a metal oxide.
As the process without using the vacuum vapor deposition, a process for forming a polarizing coating film on the curved surface of a lens in which a flat plate and a lens are placed in a manner such that axes of the flat plate and the lens are placed at different positions, the spin coating with a polarizing solution is conducted while the polarizing solution is supplied at the center of the flat plate so that the polarizing solution makes a shear flow on the curved surface of the lens, and the polarizing solution is cured, is proposed (for example, refer to Patent Literature 2).